During the period from 1982 to 1990, we operated on 25 patients with cardiac cachexia associated with a long history of combined mitral and tricuspid diseases. The age distribution was 44 to 68 years, with an average of 58 years. The overall operative mortality was 28 percent (7/25). However, the operative mortality differed according to various factors. Patients with preoperative nutritional support had a mortality rate of 17 percent, as compared with 57 percent for those without nutritional support (p < 0.05). The operative mortality was higher in patients with giant left atrium (39 percent vs 0 percent, p < 0.01). The postoperative cardiothoracic ratio in chest radiographs was significantly decreased by left atrial plication (91.6 percent vs 74.1 percent, p < 0.05). However, the operative mortality in patients with plication was still higher than in patients whose left atrium was left intact (67 percent vs 16 percent, p < 0.025). Advanced age, female sex, advanced tricuspid regurgitation, preoperative renal failure (serum urea nitrogen > 30 mg/dl), and hepatic failure (ascites or serum total bilirubin > 2.5 mg/dl) had no significant effects on operative mortality. The results demonstrated that preoperative nutritional support resulted in significant decreases in the incidence of postoperative respiratory failure and operative mortality. In contrast, postoperative respiratory failure occurred in a high percentage of patients without nutritional support even though left atrial plication was successfully performed.